The prior art x-ray imaging systems include projection radiography, geometric tomography, projection radiography, computed axial tomography, and digital x-ray tomosynthesis methods, as described here. These x-ray systems have many applications, especially medical imaging and security applications such as baggage imaging. Projection radiography is a imaging technique involving an x-ray point source that emits a cone beam of x-rays through an object, and a two-dimensional x-ray image sensor (i.e. x-ray film or digital x-ray image sensor, for example) that measures the spatially varying attenuation of the x-ray cone beam after is passes through the object.